Computational biology UNIT 1

surrounds the cell's cytoplasm and regulates the flow of substances in and out of the cell MADE UP OF phospholipids and proteins

long, whip-like protrusions that aids in cellular locomotion used by both gram positive and gram negative organisms

Outer covering of most cells that protects the bacterial cell and gives it shape

Made up of peptidoglycon

a gel like substance composed mainly of water that also contains enzymes, salts, cell components and various organic molecules

cell structure responsible for protein production

Area of the cytoplasm that contains the prokaryote's single DNA molecule

A glycoprotein\-polysaccharide covering that surrounds the cell membranes

It contains the inclusion bodies like ribosomes and larger masses scattered in the cytoplasmic matrix

The cell membrane is the outer layer of the living cell. It controls the passage of materials into and out of the cell.

The membrane as an inner and outer dense protein layer surrounding a thicker but less dense phospholipid layer which contains ion gated channels.

• The nucleus is a round or oval body lying in the center of the cell. It is surrounded by a double membrane, the nuclear membrane or envelope.

• Within the nucleus, one or more nucleoli may be seen. These are dense bodies containing the subunits for the ribosomes, the cytoplasmic organelles involved in the synthesis of protein.

• It is usually attached to a specific chromosome in the nucleus the chromosomes look like a single network of thin threads. The gene material of the cell is found in the chromosomes

• Centrioles are present as a pair of cylindrical rods in many eukaryotic cells.

• Centrioles play a role in the formation of the spindle apparatus, which is an essential feature of both mitosis and meiosis

• Mitochondria are rounded or cigar-shaped organelle's that are particularly prominent in cells with high metabolic activity (like muscle cells)

• Mitochondria have a double wall: an outer smooth membrane which forms the outer boundary and an inner membrane which is extensively folded. The folds, or cristae, project into the interior of the organelle and have a variety of enzymes embedded in them.
• during cellular respiration, the mitochondria make ATP molecules that provide the energy for all the cell activities
• These enzymes are involved in the systematic degradation of organic molecules to yield energy for the cell. Like

• In many parts of the cell, the endoplasmic reticulum is associated with small dense granules lying along the outer border of its membrane. These structures are known as ribosomes. They impart a rough appearance to the endoplasmic reticulum, so that the ER is called the rough endoplasmic reticulum (RER) in these regions, which are usually associated with active protein synthesis.

• The prime rough endoplasmic reticulum function is the production and processing of specific proteins at ribosomal sites that are later exported.

• The next rough endoplasmic reticulum function is to transport these ready proteins to the sites where they are required.

• Smooth endoplasmic reticulum is found in a variety of cell types and it serves different functions in each. It consists of tubules and vesicles that branch forming a network.

⚫ IT is associated with cellular regions which are involved in the synthesis and transport of lipids or the detoxification of a variety of poisons.

⚫ The network of smooth endoplasmic reticulum allows increased surface area for the action or storage of key enzymes and the products of these enzymes RIBOSOMES

• Ribosomes are the components of cells that make proteins from all amino acids

• ribosomes may wander freely within the cytoplasm or attach to the endoplasmic reticulum

• DNA is used to make RNA, which, in turn, is used to make protein.

• Ribosomes are made from complexes of RNAS and proteins. Ribosomes are divided into two subunits, one larger than the other.

• The smaller subunit binds to the mRNA, while the larger subunit binds to the tRNA and the amino acids.

• They exist as stacks of flattened sacs, or vesicles that are continuous with the channels of the SER

• Their major function is the storage, modification, and packing of materials produced for secretory export, since these organelles are particularly prominent in secretory cells such as those of the pancreas

• The Golgi apparatus may actually be part of a dynamic system of membranous channels within the cell in which all elements such as the nuclear envelope, the ER, the Golgi apparatus, and the cell membrane are connected to each other without sharp boundaries

• Lysosomes contain hydrolyzing enzymes that would digest the cellular contents if they were not contained within the impermeable lysosomal membrane. Rupture of this membrane releases these enzymes

• The lysosome plays a role in intracellular digestion and may also be important in the destruction of certain structures during the process of development

• They are frequently nicknamed "suicide-bags" or "suicide-sacs" by cell biologists due to their role in autolysis.

• Vacuoles are discrete, clear regions within the cell that contain water and dissolved materials

• The vacuole may act as a reservoir for fluids and salts that might otherwise interfere with metabolic processes occurring in the cytoplasm

• is inside nucleus
• this is where ribosom

• includes thread like microfilaments which are made of protein
and microtubules which are thin hollow tubes

• it is where photosynthesis happen